Dear Mohamed,
as somebody already said, there is not a single scanner wich can cover -all- these components
(silver bullet), you will have better luck using different scanners for different components.

Like everybody said, Nessus is the most general/overall solution.

That been said, if you're serious about your systems security (as I think you are, because you're
looking for a complete scanner solution) I strongly recommend using a professional pentester,
review, among other things, the source code of your applications and educate your programmers and
network administrators. These are the -only- things that will effectively reduce your risk and can
give you a -real- measure of your systems security.

Scanners only should NOT be used to do a -real- evaluation as this is misleading.